Best sub-$100 "children's tablet"

The family is considering going in on some tablets for my siblings' children.

Does anyone have experience with any of the kids tablets out there? My initial instinct is to go for the Nook HD for the sake of in-store support, but I haven't looked particularly hard at the low-end tablet market and I want to make sure there isn't a notably better option out there.

Has anyone really dug through these cheap tablets enough to be able to recommend any of them?

I appreciate any help ya'll can offer.

- Devin